Journal ArticleDOI
Vector wave analysis of broadband multimode optical fibers with optimum refractive index distribution
TLDR
In this paper, a vector wave analysis is presented of a multimode optical fiber with an α-power law index profile that includes an additional fourth-order term, and the ultimate limit of the width of the impulse response is derived.Abstract:
A vector wave analysis is presented of a multimode optical fiber with an α-power law index profile that includes an additional fourth-order term. By optimizing a and the coefficient of the fourth-order term, the ultimate limit of the width of the impulse response is derived. The effect of the second-order material dispersion of the refractive index is completely compensated by the fourth-order term in the index distribution. As a result, the rms width of the impulse response is reduced to 20 ps/km, one-fifth of the value achievable with the ordinary a-power distribution, even if all modes carry equal power and there is no mode coupling. For a fiber whose normalized frequency is less than 40, the ultimate width of the impulse response is determined by the term with the gradient of the square of the index or ∇n2 in the wave equation.read more
Citations
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Journal ArticleDOI
Exact expressions for scalar modal eigenvalues and group delays in power-law optical fibers
TL;DR: In this paper, the exact modal propagation constants and group delays for noncircular fibers of power-law type were derived for an infinite profile, and the results of the exact, WKB, and geometric optics theories were all shown to agree.
Journal ArticleDOI
Numerical calculation of optimum α for a germania-doped silica lightguide
TL;DR: In this article, the optimum refractive index profile parameter α for a germania-doped silica lightguide was determined using an exact numerical solution to Maxwell's equations, and the results agreed with the earlier work of Olshansky and Keck and with the work of Marcatili.
Journal ArticleDOI
Comparison of vector and scalar modes in a lightguide with a hyperbolic secant index distribution
TL;DR: In this article, the authors examined the properties of the scalar modes in an infinite lens-like medium and the vector modes in a self-focusing fiber with an infinite homogeneous cladding for a hyperbolic secant index distribution.
References
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TL;DR: Simple formulas and functions for the fiber parameters are presented as a help for practical design work that considers the propagation constant, mode delay, the cladding field depth, and the power distribution in the fiber cross section.
Journal ArticleDOI
Multimode theory of graded-core fibers
D. Gloge,E. A. J. Marcatili +1 more
TL;DR: In this paper, a general class of circular symmetric profiles which comprise the parabolic distribution and the abrupt core-cladding index step as special cases are considered. And a relation is derived between the maximum index error and the impulse response, the mode volume, and the near and far field power distributions.
Journal ArticleDOI
An Optical Waveguide with the Optimum Distribution of the Refractive Index with Reference to Waveform Distortion
S. Kawakami,J. Nishizawa +1 more
TL;DR: In this article, it was shown that the group velocities of different modes can be made the same if an appropriate distribution of the refractive index in the guide is realized, and the group velocity is also independent of frequencies if the medium is dispersion free.
Journal ArticleDOI
Analysis of Wave Propagation in Optical Fibers Having Core with alpha-Power Refractive-Index Distribution and Uniform Cladding
K. Okamoto,T. Okoshi +1 more
TL;DR: In this article, a closed-form characteristic equation was derived from the variational formulation of the wave propagation in an optical fiber, provided that the permittivity in the core is proportional to r/sup alpha, where r is the radial coordinate and 1 < alpha < /spl infin/, and the cladding is uniform.
Journal ArticleDOI
Analysis of Wave Propagation in Inhomogeneous Optical Fibers Using a Variational Method
Takanori Okoshi,K. Okamoto +1 more
TL;DR: In this article, a variational method is used to determine the propagation characteristics of an optical fiber consisting of a core with an arbitrary refractive-index distribution and a uniform cladding, and the obtained characteristic equations for the simplest case (uniform core case) are compared with analytic solutions to ensure the validity of the analysis.